Glen Watson said that the census collects data that's going to provide "a bedrock of information for the next 10 years".

He was responding to questions on BBC Radio 4's Today programme about whether there was still a need for the population survey, which is carried out every 10 years. The collection of such information in England and Wales allows local councils, central government and businesses to plan services that families and communities need.

The census has been criticised for the lack of participation from the public and for forms containing inaccurate information being returned. Watson conceded that there have been problems in the past.

"Well every census is a little difficult. I mean the 2001 census in most respects was a success, and has been used ever since to allocate funding out to local areas and has been used to plan services. So there were some particular problems, but that's why we've improved the arrangements for 2011," he said.

"We're producing a new address register to underpin this and we're providing an online internet completion option for the first time, we're providing a questionnaire tracking system, which means we'll know on a day by day basis who has and who hasn't returned their questionnaires, and there's a lot of improvements built in."

Daniel Hamilton, campaign director at Big Brother Watch and fellow guest on the show, argued that the census was a duplication of information already held by the government.

"Having a self completion form is an incredibly ineffective and an intrusive way of getting the information that the government already has," he said.

He added that the government should collate data that it holds already in "a much more sensible way".

Privacy campaigners NO2ID has also hit out at the survey, describing it as "pointless, out of date and wasteful".

"If David Cameron and Nick Clegg want to show that they mean their fine words about rolling back the database state, then they will reverse the stealthy changes that have been made to census confidentiality," said Guy Herbert, general secretary of NO2ID.

"The government should commit itself to keep census information fully confidential, and to destroy all the raw data when it has been statistically tabulated, so that it cannot be used for other purposes."

Last year Cabinet Office minister Francis Maude said that there were cheaper and quicker ways of collecting population information and other statistics. He suggested that it could be done more regularly and accurately using various databases.